An experimental and kinetic modeling study of ethyl tert-butyl ether. Part I: High-temperature pyrolysis and oxidation chemistry

Liu, Jiaxin, Chen, Jin-Tao, Khan-Ghauri, Maryam, Jacobs, Joseph E., Grégoire, Claire M., Mathieu, Olivier, Petersen, Eric L., Senecal, Peter K., Zhou, Chong-Wen, Curran, Henry J. (2025). An experimental and kinetic modeling study of ethyl tert-butyl ether. Part I: High-temperature pyrolysis and oxidation chemistry. Combustion and Flame, 281, 114394. https://doi.org/10.1016/j.combustflame.2025.114394

Abstract

A comprehensive experimental and kinetic modeling study of the combustion of ethyl tert-butyl ether (ETBE) is conducted over a wide range of engine-relevant conditions. Part I focuses exclusively on the high-temperature chemistry including relevant experimental pyrolysis and high-temperature oxidative validation targets. Part II focuses on the low- to intermediate temperature chemistry of ETBE and uses ignition delay times to validate the mechanism. CO time-history profiles from highly-diluted ETBE pyrolysis are measured behind reflected shock waves with a spectroscopic laser diagnostic in the 1235–1528 K temperature range near atmospheric pressure. Laminar flame speed (LFS) measurements of ETBE oxidation in air are conducted at 1 and 3 atm in the equivalence ratio range of 0.7–1.6. Reaction classes involving unimolecular decomposition, hydrogen atom abstraction, fuel radical β-scission and isomerization reactions are included to describe the high-temperature chemistry using the GalwayMech1.0 core C0–C4 chemistry. Sensitivity analyses reveal that the rate constant of the elimination reaction ETBE ⇌ IC4H8 + C2H5OH is very important to species profile predictions, followed by the two C–O bond breaking channels. Hence, pressure- and temperature-dependent rate constants for the two alcohol elimination channels: (a) ETBE ⇌ IC4H8 + C2H5OH and (b) ETBE ⇌ TC4H9OH + C2H4 were calculated using quantum chemistry. Similarly, the C–O bond β-scission reaction of ETBE radical, ETBE-S ⇌ TĊ4H9 + CH3CHO was also calculated in this study. The LFS predictions are dominated by the C0–C2 core chemistry with the fuel chemistry not appearing to be sensitive.

Funder

China Scholarship Council
Computational Chemistry Consortium
Science Foundation Ireland

Publisher

Elsevier and Combustion Institute

Rights

CC BY

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Collections

School of Biological and Chemical Sciences (Scholarly Articles)